1
|
Xiong T, Zhang Z, Fan T, Ye F, Ye Z. Origin, evolution, and diversification of inositol 1,4,5-trisphosphate 3-kinases in plants and animals. BMC Genomics 2024; 25:350. [PMID: 38589807 PMCID: PMC11000326 DOI: 10.1186/s12864-024-10257-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 03/26/2024] [Indexed: 04/10/2024] Open
Abstract
BACKGROUND In Eukaryotes, inositol polyphosphates (InsPs) represent a large family of secondary messengers and play crucial roes in various cellular processes. InsPs are synthesized through a series of pohophorylation reactions catalyzed by various InsP kinases in a sequential manner. Inositol 1,4,5-trisphosphate 3-kinase (IP3 3-kinase/IP3K), one member of InsP kinase, plays important regulation roles in InsPs metabolism by specifically phosphorylating inositol 1,4,5-trisphosphate (IP3) to inositol 1,3,4,5-tetrakisphosphate (IP4) in animal cells. IP3Ks were widespread in fungi, plants and animals. However, its evolutionary history and patterns have not been examined systematically. RESULTS A total of 104 and 31 IP3K orthologues were identified across 57 plant genomes and 13 animal genomes, respectively. Phylogenetic analyses indicate that IP3K originated in the common ancestor before the divergence of fungi, plants and animals. In most plants and animals, IP3K maintained low-copy numbers suggesting functional conservation during plant and animal evolution. In Brassicaceae and vertebrate, IP3K underwent one and two duplication events, respectively, resulting in multiple gene copies. Whole-genome duplication (WGD) was the main mechanism for IP3K duplications, and the IP3K duplicates have experienced functional divergence. Finally, a hypothetical evolutionary model for the IP3K proteins is proposed based on phylogenetic theory. CONCLUSION Our study reveals the evolutionary history of IP3K proteins and guides the future functions of animal, plant, and fungal IP3K proteins.
Collapse
Affiliation(s)
- Tao Xiong
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China
- College of Life Science, Xinyang Normal University, Xinyang, Henan, China
| | - Zaibao Zhang
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China.
- College of Life Science, Xinyang Normal University, Xinyang, Henan, China.
| | - Tianyu Fan
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China
| | - Fan Ye
- College of Forestry and Biotechnology, Zhejiang A & F University, Hangzhou, Zhejiang, China
| | - Ziyi Ye
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China
| |
Collapse
|
2
|
Márquez-Moñino MÁ, Ortega-García R, Whitfield H, Riley AM, Infantes L, Garrett SW, Shipton ML, Brearley CA, Potter BVL, González B. Substrate promiscuity of inositol 1,4,5-trisphosphate kinase driven by structurally-modified ligands and active site plasticity. Nat Commun 2024; 15:1502. [PMID: 38374076 PMCID: PMC10876669 DOI: 10.1038/s41467-024-45917-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Accepted: 02/05/2024] [Indexed: 02/21/2024] Open
Abstract
D-myo-inositol 1,4,5-trisphosphate (InsP3) is a fundamental second messenger in cellular Ca2+ mobilization. InsP3 3-kinase, a highly specific enzyme binding InsP3 in just one mode, phosphorylates InsP3 specifically at its secondary 3-hydroxyl group to generate a tetrakisphosphate. Using a chemical biology approach with both synthetised and established ligands, combining synthesis, crystallography, computational docking, HPLC and fluorescence polarization binding assays using fluorescently-tagged InsP3, we have surveyed the limits of InsP3 3-kinase ligand specificity and uncovered surprisingly unforeseen biosynthetic capacity. Structurally-modified ligands exploit active site plasticity generating a helix-tilt. These facilitated uncovering of unexpected substrates phosphorylated at a surrogate extended primary hydroxyl at the inositol pseudo 3-position, applicable even to carbohydrate-based substrates. Crystallization experiments designed to allow reactions to proceed in situ facilitated unequivocal characterization of the atypical tetrakisphosphate products. In summary, we define features of InsP3 3-kinase plasticity and substrate tolerance that may be more widely exploitable.
Collapse
Affiliation(s)
- María Ángeles Márquez-Moñino
- Department of Crystallography and Structural Biology, Institute of Physical-Chemistry Blas Cabrera, CSIC, Serrano 119, 28006, Madrid, Spain
| | - Raquel Ortega-García
- Department of Crystallography and Structural Biology, Institute of Physical-Chemistry Blas Cabrera, CSIC, Serrano 119, 28006, Madrid, Spain
| | - Hayley Whitfield
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Andrew M Riley
- Drug Discovery and Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Lourdes Infantes
- Department of Crystallography and Structural Biology, Institute of Physical-Chemistry Blas Cabrera, CSIC, Serrano 119, 28006, Madrid, Spain
| | - Shane W Garrett
- Wolfson Laboratory of Medicinal Chemistry, Department of Life Sciences, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Megan L Shipton
- Drug Discovery and Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
| | - Charles A Brearley
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Barry V L Potter
- Drug Discovery and Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
- Wolfson Laboratory of Medicinal Chemistry, Department of Life Sciences, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Beatriz González
- Department of Crystallography and Structural Biology, Institute of Physical-Chemistry Blas Cabrera, CSIC, Serrano 119, 28006, Madrid, Spain.
| |
Collapse
|
3
|
Zhang X, He J, Ren D. Commentary on: The actin bundling activity of ITPKA mainly accounts for its migration-promoting effect in lung cancer cells. Biosci Rep 2023; 43:BSR20230057. [PMID: 37664985 PMCID: PMC10500224 DOI: 10.1042/bsr20230057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 08/24/2023] [Accepted: 09/01/2023] [Indexed: 09/05/2023] Open
Abstract
1,4,5-triphosphate 3-kinase A (ITPKA) was first described and characterized by Irvine et al. in 1986 and cloned by Takazawa et al. in 1990. It is one of the components of the Ca2+ and calmodulin signaling pathway and a substrate for cAMP-dependent kinase (PKA) and protein kinase C (PKC), and is mainly involved in the regulation of intracellular inositol polyphosphate signaling molecules. Through a series of studies, Sabine's team has found that ITPKA expression was up-regulated in a variety of cancer cells, and silencing ITPKA inhibited while overexpressing ITPKA promoted cancer cell migration in vitro and metastasis in vivo. The latest research from Sabine's team has demonstrated that in H1299 lung cancer cells, the mechanism by which ITPKA promoted migration and invasion was predominantly depending on the ability of binding to F-actin, which will induce cancer cells to form a tight flexible actin networks. Small molecule compounds targeting the IP3 kinase activity of ITPKA protein may only inhibit the migration and invasion of cancer cells caused by the enhanced ITPKA kinase activity under ATP stimulation, but not the cytoskeletal remodeling caused by the binding of ITPKA protein to F-actin and the driven migration and invasion of cancer cells. Therefore, targeted therapeutic strategy focusing on blocking the binding of ITPKA to F-actin is indispensable when designing the inhibitors targeting ITPKA protein.
Collapse
Affiliation(s)
- Xin Zhang
- Postdoctoral Innovation Practice Base, Postdoctoral Research Center of Jiangmen Central Hospital, Southern Medical University, Jiangmen 529030, China
- Clinical Experimental Center, Jiangmen Key Laboratory of Clinical Biobank and Translational Research, Jiangmen Central Hospital, Jiangmen 529030, China
| | - Jiadi He
- Clinical Experimental Center, Jiangmen Key Laboratory of Clinical Biobank and Translational Research, Jiangmen Central Hospital, Jiangmen 529030, China
| | - Dong Ren
- Department of Pathology, University of California Irvine Medical Center, Orange, CA 92868, U.S.A
| |
Collapse
|
4
|
Mackrill JJ. Non-inositol 1,4,5-trisphosphate (IP3) receptor IP3-binding proteins. BIOCHIMICA ET BIOPHYSICA ACTA (BBA) - MOLECULAR CELL RESEARCH 2023; 1870:119470. [PMID: 37011730 DOI: 10.1016/j.bbamcr.2023.119470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/23/2023] [Accepted: 03/23/2023] [Indexed: 04/03/2023]
Abstract
Conventionally, myo-D-inositol 1, 4,5-trisphosphate (IP3) is thought to exert its second messenger effects through the gating of IP3R Ca2+ release channels, located in Ca2+-storage organelles like the endoplasmic reticulum. However, there is considerable indirect evidence to support the concept that IP3 might interact with other, non-IP3R proteins within cells. To explore this possibility further, the Protein Data Bank was searched using the term "IP3". This resulted in the retrieval of 203 protein structures, the majority of which were members of the IP3R/ryanodine receptor superfamily of channels. Only 49 of these structures were complexed with IP3. These were inspected for their ability to interact with the carbon-1 phosphate of IP3, since this is the least accessible phosphate group of its precursor, phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). This reduced the number of structures retrieved to 35, of which 9 were IP3Rs. The remaining 26 structures represent a diverse range of proteins, including inositol-lipid metabolizing enzymes, signal transducers, PH domain containing proteins, cytoskeletal anchor proteins, the TRPV4 ion channel, a retroviral Gag protein and fibroblast growth factor 2. Such proteins may impact on IP3 signalling and its effects on cell-biology. This represents an area open for exploration in the field of IP3 signalling.
Collapse
Affiliation(s)
- John James Mackrill
- Department of Physiology, University College Cork, Western Gateway Building, Western Road, Cork T12 XF62, Ireland.
| |
Collapse
|
5
|
Myo-D-inositol Trisphosphate Signalling in Oomycetes. Microorganisms 2022; 10:microorganisms10112157. [DOI: 10.3390/microorganisms10112157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 10/21/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022] Open
Abstract
Oomycetes are pathogens of plants and animals, which cause billions of dollars of global losses to the agriculture, aquaculture and forestry sectors each year. These organisms superficially resemble fungi, with an archetype being Phytophthora infestans, the cause of late blight of tomatoes and potatoes. Comparison of the physiology of oomycetes with that of other organisms, such as plants and animals, may provide new routes to selectively combat these pathogens. In most eukaryotes, myo-inositol 1,4,5 trisphosphate is a key second messenger that links extracellular stimuli to increases in cytoplasmic Ca2+, to regulate cellular activities. In the work presented in this study, investigation of the molecular components of myo-inositol 1,4,5 trisphosphate signaling in oomycetes has unveiled similarities and differences with that in other eukaryotes. Most striking is that several oomycete species lack detectable phosphoinositide-selective phospholipase C homologues, the enzyme family that generates this second messenger, but still possess relatives of myo-inositol 1,4,5 trisphosphate-gated Ca2+-channels.
Collapse
|
6
|
TNP Analogues Inhibit the Virulence Promoting IP3-4 Kinase Arg1 in the Fungal Pathogen Cryptococcus neoformans. Biomolecules 2022; 12:biom12101526. [PMID: 36291735 PMCID: PMC9599641 DOI: 10.3390/biom12101526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/29/2022] Open
Abstract
New antifungals with unique modes of action are urgently needed to treat the increasing global burden of invasive fungal infections. The fungal inositol polyphosphate kinase (IPK) pathway, comprised of IPKs that convert IP3 to IP8, provides a promising new target due to its impact on multiple, critical cellular functions and, unlike in mammalian cells, its lack of redundancy. Nearly all IPKs in the fungal pathway are essential for virulence, with IP3-4 kinase (IP3-4K) the most critical. The dibenzylaminopurine compound, N2-(m-trifluorobenzylamino)-N6-(p-nitrobenzylamino)purine (TNP), is a commercially available inhibitor of mammalian IPKs. The ability of TNP to be adapted as an inhibitor of fungal IP3-4K has not been investigated. We purified IP3-4K from the human pathogens, Cryptococcus neoformans and Candida albicans, and optimised enzyme and surface plasmon resonance (SPR) assays to determine the half inhibitory concentration (IC50) and binding affinity (KD), respectively, of TNP and 38 analogues. A novel chemical route was developed to efficiently prepare TNP analogues. TNP and its analogues demonstrated inhibition of recombinant IP3-4K from C. neoformans (CnArg1) at low µM IC50s, but not IP3-4K from C. albicans (CaIpk2) and many analogues exhibited selectivity for CnArg1 over the human equivalent, HsIPMK. Our results provide a foundation for improving potency and selectivity of the TNP series for fungal IP3-4K.
Collapse
|
7
|
Kröber T, Bartsch SM, Fiedler D. Pharmacological tools to investigate inositol polyphosphate kinases - Enzymes of increasing therapeutic relevance. Adv Biol Regul 2021; 83:100836. [PMID: 34802993 DOI: 10.1016/j.jbior.2021.100836] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 01/01/2023]
Abstract
Inositol poly- and pyrophosphates (InsPs and PP-InsPs) are a group of central eukaryotic metabolites and signaling molecules. Due to the diverse cellular functions and widespread diseases InsPs and PP-InsPs are associated with, pharmacological targeting of the kinases involved in their biosynthesis has become a significant research interest in the last decade. In particular, the development of inhibitors for inositol hexakisphosphate kinases (IP6Ks) has leaped forward, while other inositol phosphate kinases have received scant attention. This review summarizes the efforts undertaken so far for discovering potent and selective inhibitors for this diverse group of small molecule kinases. The benefits of pharmacological inhibition are highlighted, given the multiple kinase-independent functions of inositol phosphate kinases. The distinct structural families of InsP and PP-InsP kinases are presented, and we discuss how compound availability for different inositol phosphate kinase families varies drastically. Lead compound discovery and optimization for the inositol kinases would benefit from detailed structural information on the ATP-binding sites of these kinases, as well as reliable biochemical and cellular read-outs to monitor inositol phosphate kinase activity in complex settings. Efforts to further tune well-established inhibitors, while simultaneously reviving tool compound development for the more neglected kinases from this family are indisputably worthwhile, considering the large potential therapeutic benefits.
Collapse
Affiliation(s)
- Tim Kröber
- Leibniz Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125, Berlin, Germany; Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, 12489, Berlin, Germany.
| | - Simon M Bartsch
- Leibniz Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125, Berlin, Germany; Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, 12489, Berlin, Germany.
| | - Dorothea Fiedler
- Leibniz Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125, Berlin, Germany; Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, 12489, Berlin, Germany.
| |
Collapse
|
8
|
Mechanism of BIP-4 mediated inhibition of InsP3Kinase-A. Biosci Rep 2021; 41:229216. [PMID: 34232294 PMCID: PMC8292763 DOI: 10.1042/bsr20211259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/02/2021] [Accepted: 07/02/2021] [Indexed: 11/17/2022] Open
Abstract
Overexpression of the neuronal InsP3kinase-A increases malignancy of different tumor types. Since InsP3kinase-A highly selectively binds Ins(1,4,5)P3, small molecules competing with Ins(1,4,5)P3 provide a promising approach for the therapeutic targeting of InsP3kinase-A. Based on this consideration, we analyzed the binding mechanism of BIP-4 (2-[3,5-dimethyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl]-5, 8-dinitro-1H-benzo[de]isoquinoline-1,3(2H)-dione), a known competitive small-molecule inhibitor of Ins(1,4,5)P3. We tested a total of 80 BIP-4 related compounds in biochemical assays. The results of these experiments revealed that neither the nitrophenyl nor the benzisochinoline group inhibited InsP3kinase-A activity. Moreover, none of the BIP-4 related compounds competed for Ins(1,4,5)P3, demonstrating the high selectivity of BIP-4. To analyze the inhibition mechanism of BIP-4, mutagenesis experiments were performed. The results of these experiments suggest that the nitro groups attached to the benzisochinoline ring compete for binding of Ins(1,4,5)P3 while the nitrophenyl group is associated with amino acids of the ATP-binding pocket. Our results now offer the possibility to optimize BIP-4 to design specific InsP3Kinase-A inhibitors suitable for therapeutic targeting of the enzyme.
Collapse
|
9
|
Ran M, Huang H, Hu B, Hu S, Hu J, Li L, He H, Liu H, Wang J. Comparative Analysis of Testicular Histology and lncRNA-mRNA Expression Patterns Between Landes Geese ( Anser anser) and Sichuan White Geese ( Anser cygnoides). Front Genet 2021; 12:627384. [PMID: 33737948 PMCID: PMC7963104 DOI: 10.3389/fgene.2021.627384] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/20/2021] [Indexed: 11/13/2022] Open
Abstract
Landes geese and Sichuan White geese are two important genetic materials for commercial goose breeding. However, the differences in the male reproductive capacity between these two breeds and the potential molecular mechanisms and associated key genes have not been reported to date. The present study compared the testicular histology and mRNA-long non-coding RNA (lncRNA) expression patterns to reveal the differences in male reproductive performance between Sichuan White geese and Landes geese, as well as to explore the underlying molecular mechanisms. Histological results showed that the testicular organ index, semen volume, and long diameter of seminiferous tubules of Landes geese were significantly larger than those of Sichuan White geese. Analyses of mRNA-lncRNA expression profile showed that compared with Sichuan White geese, a total of 462 differentially expressed mRNAs (DEGs) (173 up-regulated and 289 down-regulated) and 329 differentially expressed lncRNAs (DE lncRNAs) (280 up-regulated, 49 down-regulated) were identified in Landes geese. Among these DEGs, there were 10 spermatogenesis-related and highly expressed (FPKM > 10) DEGs. Except for SEPP1, all of these DEGs were significantly up-regulated in the testes of Landes geese. Functional enrichment analysis indicated that the pathway related to metabolism progress and phosphoinositol signal is vitally responsible for differences in male reproductive performance between Landes geese and Sichuan White geese. These results show that compared with Sichuan White geese, the spermatogenesis in the testis of Landes geese was more active, which may be mainly related to the inositol phosphate signal. These data contribute to a better understanding of the mechanisms underlying different male reproductive performances between Landes geese and Sichuan White geese. This knowledge might eventually provide a theoretical basis for improving male reproductive performance in geese.
Collapse
Affiliation(s)
- Mingxia Ran
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Huaxuan Huang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Bo Hu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Shenqiang Hu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Jiwei Hu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Liang Li
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Hua He
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Hehe Liu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| | - Jiwen Wang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
| |
Collapse
|
10
|
Zhang X, Shi S, Su Y, Yang X, He S, Yang X, Wu J, Zhang J, Rao F. Suramin and NF449 are IP5K inhibitors that disrupt inositol hexakisphosphate-mediated regulation of cullin-RING ligase and sensitize cancer cells to MLN4924/pevonedistat. J Biol Chem 2020; 295:10281-10292. [PMID: 32493769 DOI: 10.1074/jbc.ra120.014375] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 05/27/2020] [Indexed: 12/27/2022] Open
Abstract
Inositol hexakisphosphate (IP6) is an abundant metabolite synthesized from inositol 1,3,4,5,6-pentakisphosphate (IP5) by the single IP5 2-kinase (IP5K). Genetic and biochemical studies have shown that IP6 usually functions as a structural cofactor in protein(s) mediating mRNA export, DNA repair, necroptosis, 3D genome organization, HIV infection, and cullin-RING ligase (CRL) deneddylation. However, it remains unknown whether pharmacological perturbation of cellular IP6 levels affects any of these processes. Here, we performed screening for small molecules that regulate human IP5K activity, revealing that the antiparasitic drug and polysulfonic compound suramin efficiently inhibits IP5K in vitro and in vivo The results from docking experiments and biochemical validations suggested that the suramin targets IP5K in a distinct bidentate manner by concurrently binding to the ATP- and IP5-binding pockets, thereby inhibiting both IP5 phosphorylation and ATP hydrolysis. NF449, a suramin analog with additional sulfonate moieties, more potently inhibited IP5K. Both suramin and NF449 disrupted IP6-dependent sequestration of CRL by the deneddylase COP9 signalosome, thereby affecting CRL activity cycle and component dynamics in an IP5K-dependent manner. Finally, nontoxic doses of suramin, NF449, or NF110 exacerbate the loss of cell viability elicited by the neddylation inhibitor and clinical trial drug MLN4924/pevonedistat, suggesting synergistic ef-fects. Suramin and its analogs provide structural templates for designing potent and specific IP5K inhibitors, which could be used in combination therapy along with MLN4924/pevonedistat. IP5K is a potential mechanistic target of suramin, accounting for suramin's therapeutic effects.
Collapse
Affiliation(s)
- Xiaozhe Zhang
- College of Biological Sciences, China Agricultural University, Beijing, China.,Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Shaodong Shi
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yang Su
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Xiaoli Yang
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Sining He
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Xiuyan Yang
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Jing Wu
- Key Laboratory of Cell Differentiation and Apoptosis, Ministry of Education, Department of Pathophysiology, Ruijin Hospital, Shanghai Jiao-Tong University School of Medicine, Shanghai, China
| | - Jian Zhang
- Key Laboratory of Cell Differentiation and Apoptosis, Ministry of Education, Department of Pathophysiology, Ruijin Hospital, Shanghai Jiao-Tong University School of Medicine, Shanghai, China
| | - Feng Rao
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| |
Collapse
|
11
|
McNamara DE, Dovey CM, Hale AT, Quarato G, Grace CR, Guibao CD, Diep J, Nourse A, Cai CR, Wu H, Kalathur RC, Green DR, York JD, Carette JE, Moldoveanu T. Direct Activation of Human MLKL by a Select Repertoire of Inositol Phosphate Metabolites. Cell Chem Biol 2019; 26:863-877.e7. [PMID: 31031142 DOI: 10.1016/j.chembiol.2019.03.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 02/08/2019] [Accepted: 03/15/2019] [Indexed: 12/29/2022]
Abstract
Necroptosis is an inflammatory form of programmed cell death executed through plasma membrane rupture by the pseudokinase mixed lineage kinase domain-like (MLKL). We previously showed that MLKL activation requires metabolites of the inositol phosphate (IP) pathway. Here we reveal that I(1,3,4,6)P4, I(1,3,4,5,6)P5, and IP6 promote membrane permeabilization by MLKL through directly binding the N-terminal executioner domain (NED) and dissociating its auto-inhibitory region. We show that IP6 and inositol pentakisphosphate 2-kinase (IPPK) are required for necroptosis as IPPK deletion ablated IP6 production and inhibited necroptosis. The NED auto-inhibitory region is more extensive than originally described and single amino acid substitutions along this region induce spontaneous necroptosis by MLKL. Activating IPs bind three sites with affinity of 100-600 μM to destabilize contacts between the auto-inhibitory region and NED, thereby promoting MLKL activation. We therefore uncover MLKL's activating switch in NED triggered by a select repertoire of IP metabolites.
Collapse
Affiliation(s)
- Dan E McNamara
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Cole M Dovey
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Andrew T Hale
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Giovanni Quarato
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Christy R Grace
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Cristina D Guibao
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jonathan Diep
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Amanda Nourse
- Molecular Interaction Analysis Shared Resource, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Casey R Cai
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Hong Wu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ravi C Kalathur
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Douglas R Green
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - John D York
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jan E Carette
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Tudor Moldoveanu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| |
Collapse
|
12
|
Shears SB, Wang H. Inositol phosphate kinases: Expanding the biological significance of the universal core of the protein kinase fold. Adv Biol Regul 2019; 71:118-127. [PMID: 30392847 PMCID: PMC9364425 DOI: 10.1016/j.jbior.2018.10.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 10/23/2018] [Accepted: 10/26/2018] [Indexed: 05/06/2023]
Abstract
The protein kinase family is characterized by substantial conservation of architectural elements that are required for both ATP binding and phosphotransferase activity. Many of these structural features have also been identified in homologous enzymes that phosphorylate a variety of alternative, non-protein substrates. A comparative structural analysis of these different kinase sub-classes is a portal to a greater understanding of reaction mechanisms, enzyme regulation, inhibitor-development strategies, and superfamily-level evolutionary relationships. To serve such advances, we review structural elements of the protein kinase fold that are conserved in the subfamily of inositol phosphate kinases (InsPKs) that share a PxxxDxKxG catalytic signature: inositol 1,4,5-trisphosphate kinase (IP3K), inositol hexakisphosphate kinase (IP6K), and inositol polyphosphate multikinase (IPMK). We describe conservation of the fundamental two-lobe kinase architecture: an N-lobe constructed upon an anti-parallel β-strand scaffold, which is coupled to a largely helical C-lobe by a single, adenine-binding hinge. This equivalency also includes a G-loop that embraces the β/γ-phosphates of ATP, a transition-state stabilizing residue (Lys/His), and a Mg-positioning aspartate residue within a catalytic triad. Furthermore, we expand this list of conserved structural features to include some not previously identified in InsPKs: a 'gatekeeper' residue in the N-lobe, and an 'αF'-like helix in the C-lobe that anchors two structurally-stabilizing, hydrophobic spines, formed from non-consecutive residues that span the two lobes. We describe how this wide-ranging structural homology can be exploited to develop lead inhibitors of IP6K and IPMK, by using strategies similar to those that have generated ATP-competing inhibitors of protein-kinases. We provide several examples to illustrate how such an approach could benefit human health.
Collapse
Affiliation(s)
- Stephen B Shears
- Inositol Signaling Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| | - Huanchen Wang
- Inositol Signaling Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| |
Collapse
|
13
|
Seacrist CD, Blind RD. Crystallographic and kinetic analyses of human IPMK reveal disordered domains modulate ATP binding and kinase activity. Sci Rep 2018; 8:16672. [PMID: 30420721 PMCID: PMC6232094 DOI: 10.1038/s41598-018-34941-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 10/26/2018] [Indexed: 11/09/2022] Open
Abstract
Inositol polyphosphate multikinase (IPMK) is a member of the IPK-superfamily of kinases, catalyzing phosphorylation of several soluble inositols and the signaling phospholipid PI(4,5)P2 (PIP2). IPMK also has critical non-catalytic roles in p53, mTOR/Raptor, TRAF6 and AMPK signaling mediated partly by two disordered domains. Although IPMK non-catalytic functions are well established, it is less clear if the disordered domains are important for IPMK kinase activity or ATP binding. Here, kinetic and structural analyses of an engineered human IPMK lacking all disordered domains (ΔIPMK) are presented. Although the KM for PIP2 is identical between ΔIPMK and wild type, ΔIPMK has a 1.8-fold increase in kcat for PIP2, indicating the native IPMK disordered domains decrease IPMK activity in vitro. The 2.5 Å crystal structure of ΔIPMK is reported, confirming the conserved ATP-grasp fold. A comparison with other IPK-superfamily structures revealed a putative "ATP-clamp" in the disordered N-terminus, we predicted would stabilize ATP binding. Consistent with this observation, removal of the ATP clamp sequence increases the KM for ATP 4.9-fold, indicating the N-terminus enhances ATP binding to IPMK. Together, these structural and kinetic studies suggest in addition to mediating protein-protein interactions, the disordered domains of IPMK impart modulatory capacity to IPMK kinase activity through multiple kinetic mechanisms.
Collapse
Affiliation(s)
- Corey D Seacrist
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Raymond D Blind
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
- Departments of Pharmacology, Biochemistry and Medicine; Division of Diabetes, Endocrinology and Metabolism, Vanderbilt Diabetes Research and Training Center, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
| |
Collapse
|
14
|
Structural insights into lethal contractural syndrome type 3 (LCCS3) caused by a missense mutation of PIP5Kγ. Biochem J 2018; 475:2257-2269. [PMID: 29959184 DOI: 10.1042/bcj20180326] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Signaling molecule phosphatidylinositol 4,5-bisphosphate is produced primarily by phosphatidylinositol 4-phosphate 5-kinase (PIP5K). PIP5K is essential for the development of the human neuronal system, which has been exemplified by a recessive genetic disorder, lethal congenital contractural syndrome type 3, caused by a single aspartate-to-asparagine mutation in the kinase domain of PIP5Kγ. So far, the exact role of this aspartate residue has yet to be elucidated. In this work, we conducted structural, functional and computational studies on a zebrafish PIP5Kα variant with a mutation at the same site. Compared with the structure of the wild-type (WT) protein in the ATP-bound state, the ATP-associating glycine-rich loop of the mutant protein was severely disordered and the temperature factor of ATP was significantly higher. Both observations suggest a greater degree of disorder of the bound ATP, whereas neither the structure of the catalytic site nor the Km toward ATP was substantially affected by the mutation. Microsecond molecular dynamics simulation revealed that negative charge elimination caused by the mutation destabilized the involved hydrogen bonds and affected key electrostatic interactions in the close proximity of ATP. Taken together, our data indicated that the disease-related aspartate residue is a key node in the interaction network crucial for effective ATP binding. This work provides a paradigm of how a subtle but critical structural perturbation caused by a single mutation at the ATP-binding site abolishes the kinase activity, emphasizing that stabilizing substrate in a productive conformational state is crucial for catalysis.
Collapse
|
15
|
Saiardi A, Azevedo C, Desfougères Y, Portela-Torres P, Wilson MSC. Microbial inositol polyphosphate metabolic pathway as drug development target. Adv Biol Regul 2017; 67:74-83. [PMID: 28964726 DOI: 10.1016/j.jbior.2017.09.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 12/27/2022]
Abstract
Inositol polyphosphates are a diverse and multifaceted class of intracellular messengers omnipresent in eukaryotic cells. These water-soluble molecules regulate many aspects of fundamental cell physiology. Removing this metabolic pathway is deleterious: inositol phosphate kinase null mutations can result in lethality or substantial growth phenotypes. Inositol polyphosphate synthesis occurs through the actions of a set of kinases that phosphorylate phospholipase-generated IP3 to higher phosphorylated forms, such as the fully phosphorylated IP6 and the inositol pyrophosphates IP7 and IP8. Unicellular organisms have a reduced array of the kinases for synthesis of higher phosphorylated inositol polyphosphates, while human cells possess two metabolic routes to IP6. The enzymes responsible for inositol polyphosphate synthesis have been identified in all eukaryote genomes, although their amino acid sequence homology is often barely detectable by common search algorithms. Homology between human and microbial inositol phosphate kinases is restricted to a few catalytically important residues. Recent studies of the inositol phosphate metabolic pathways in pathogenic fungi (Cryptococcus neoformans) and protozoa (Trypanosome brucei) have revealed the importance of the highly phosphorylated inositol polyphosphates to the fitness and thus virulence of these pathogens. Given this, identification of inositol kinase inhibitors specifically targeting the kinases of pathogenic microorganisms is desirable and achievable.
Collapse
Affiliation(s)
- Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK.
| | - Cristina Azevedo
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Yann Desfougères
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Paloma Portela-Torres
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Miranda S C Wilson
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| |
Collapse
|
16
|
Oh J, Lee DG, Bahn YS, Rhee S. Crystal structure of inositol 1,3,4,5,6-pentakisphosphate 2-kinase from Cryptococcus neoformans. J Struct Biol 2017; 200:118-123. [PMID: 28919350 DOI: 10.1016/j.jsb.2017.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 11/19/2022]
Abstract
The fungal pathogen Cryptococcus neoformans is a causative agent of meningoencephalitis in humans. For its pathogenicity, the inositol polyphosphate biosynthetic pathway plays critical roles. Recently, Ipk1 from C. neoformans (CnIpk1) was identified as an inositol 1,3,4,5,6-pentakisphosphate 2-kinase that catalyzes the phosphorylation of IP5 to form IP6, a substrate for subsequent reaction to produce inositol pyrophosphates, such as PP-IP5/IP7. Furthermore, it was shown that deletion of IPK1 significantly reduces the virulence of C. neoformans, indicating that Ipk1 is a major virulence contributor. In this study, we determined a crystal structure of the apo-form of CnIpk1 at 2.35Å resolution, the first structure for a fungal Ipk1, using a single-wavelength anomalous dispersion method. Even with a low sequence similarity of 26-28%, its overall structure resembles two other Ipk1 orthologs from Arabidopsis thaliana (AtIpk1) and Mus musculus (MmIpk1), and the most crucial residues in the active site are conserved. Unlike AtIpk1 and MmIpk1, however, metal-binding sites for structural stabilization and conformational variations are absent in CnIpk1. The binding environments for substrate IP5 could be inferred by the two different binding sites for sulfate ion in CnIpk1. Taken together, these observations suggest structural similarities and discrepancies for fungal Ipk1 among members of the Ipk1 family and provide structural information for the possible development of drug design for treatment of cryptococcosis.
Collapse
Affiliation(s)
- Juntaek Oh
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Dong-Gi Lee
- Department of Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Yong-Sun Bahn
- Department of Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Sangkee Rhee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea.
| |
Collapse
|
17
|
Wang H, Shears SB. Structural features of human inositol phosphate multikinase rationalize its inositol phosphate kinase and phosphoinositide 3-kinase activities. J Biol Chem 2017; 292:18192-18202. [PMID: 28882892 DOI: 10.1074/jbc.m117.801845] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/01/2017] [Indexed: 01/17/2023] Open
Abstract
Human inositol phosphate multikinase (HsIPMK) critically contributes to intracellular signaling through its inositol-1,4,5-trisphosphate (Ins(1,4,5)P3) 3-kinase and phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) 3-kinase activities. This catalytic profile is not conserved; orthologs from Arabidopsis thaliana and Saccharomyces cerevisiae are predominantly Ins(1,4,5)P3 6-kinases, and the plant enzyme cannot phosphorylate PtdIns(4,5)P2 Therefore, crystallographic analysis of the yeast and plant enzymes, without bound inositol phosphates, do not structurally rationalize HsIPMK activities. Here, we present 1.6-Å resolution crystal structures of HsIPMK in complex with either Ins(1,4,5)P3 or PtdIns(4,5)P2 The Ins(1,4,5)P3 headgroup of PtdIns(4,5)P2 binds in precisely the same orientation as free Ins(1,4,5)P3 itself, indicative of evolutionary optimization of 3-kinase activities against both substrates. We report on nucleotide binding between the separate N- and C-lobes of HsIPMK. The N-lobe exhibits a remarkable degree of conservation with protein kinase A (root mean square deviation = 1.8 Å), indicating common ancestry. We also describe structural features unique to HsIPMK. First, we observed a constrained, horseshoe-shaped substrate pocket, formed from an α-helix, a 310 helix, and a recently evolved tri-proline loop. We further found HsIPMK activities rely on a preponderance of Gln residues, in contrast to the larger Lys and Arg residues in yeast and plant orthologs. These conclusions are supported by analyzing 14 single-site HsIPMK mutants, some of which differentially affect 3-kinase and 6-kinase activities. Overall, we structurally rationalize phosphorylation of Ins(1,4,5)P3 and PtdIns(4,5)P2 by HsIPMK.
Collapse
Affiliation(s)
- Huanchen Wang
- From the Inositol Signaling Group, Signal Transduction Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Stephen B Shears
- From the Inositol Signaling Group, Signal Transduction Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| |
Collapse
|
18
|
Franco-Echevarría E, Sanz-Aparicio J, Brearley CA, González-Rubio JM, González B. The crystal structure of mammalian inositol 1,3,4,5,6-pentakisphosphate 2-kinase reveals a new zinc-binding site and key features for protein function. J Biol Chem 2017; 292:10534-10548. [PMID: 28450399 PMCID: PMC5481561 DOI: 10.1074/jbc.m117.780395] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/25/2017] [Indexed: 12/28/2022] Open
Abstract
Inositol 1,3,4,5,6-pentakisphosphate 2-kinases (IP5 2-Ks) are part of a family of enzymes in charge of synthesizing inositol hexakisphosphate (IP6) in eukaryotic cells. This protein and its product IP6 present many roles in cells, participating in mRNA export, embryonic development, and apoptosis. We reported previously that the full-length IP5 2-K from Arabidopsis thaliana is a zinc metallo-enzyme, including two separated lobes (the N- and C-lobes). We have also shown conformational changes in IP5 2-K and have identified the residues involved in substrate recognition and catalysis. However, the specific features of mammalian IP5 2-Ks remain unknown. To this end, we report here the first structure for a murine IP5 2-K in complex with ATP/IP5 or IP6. Our structural findings indicated that the general folding in N- and C-lobes is conserved with A. thaliana IP5 2-K. A helical scaffold in the C-lobe constitutes the inositol phosphate-binding site, which, along with the participation of the N-lobe, endows high specificity to this protein. However, we also noted large structural differences between the orthologues from these two eukaryotic kingdoms. These differences include a novel zinc-binding site and regions unique to the mammalian IP5 2-K, as an unexpected basic patch on the protein surface. In conclusion, our findings have uncovered distinct features of a mammalian IP5 2-K and set the stage for investigations into protein-protein or protein-RNA interactions important for IP5 2-K function and activity.
Collapse
Affiliation(s)
- Elsa Franco-Echevarría
- From the Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física "Rocasolano," Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain and
| | - Julia Sanz-Aparicio
- From the Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física "Rocasolano," Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain and
| | - Charles A Brearley
- the School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Juana M González-Rubio
- From the Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física "Rocasolano," Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain and
| | - Beatriz González
- From the Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física "Rocasolano," Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain and
| |
Collapse
|
19
|
Inositol-1,4,5-trisphosphate 3-kinase-A (ITPKA) is frequently over-expressed and functions as an oncogene in several tumor types. Biochem Pharmacol 2017; 137:1-9. [PMID: 28377279 DOI: 10.1016/j.bcp.2017.03.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/29/2017] [Indexed: 01/22/2023]
Abstract
At present targeted tumor therapy is based on inhibition of proteins or protein mutants that are up-regulated in tumor but not in corresponding normal cells. The actin bundling Inositol-trisphosphate 3-kinase A (ITPKA) belongs to such molecular targets. ITPKA is expressed in a broad range of tumor types but shows limited expression in normal cells. In lung and breast cancer expression of ITPKA is stimulated by gene body methylation which increases with increasing malignancy of these tumors but is not detectable in the corresponding normal tissues. Since ITPKA gene body methylation occurs early in tumor development, it could serve as biomarker for early detection of lung cancer. Detailed mechanistic studies revealed that down-regulation of ITPKA in lung adenocarcinoma cancers reduced both, tumor growth and metastasis. It is assumed that tumor growth is stimulated by the InsP3Kinase activity of ITPKA and metastasis by its actin bundling activity. A selective inhibitor against the InsP3Kinase activity of ITPKA has been identified but compounds inhibiting the actin bundling activity are not available yet. Since no curative therapy option for metastatic lung or breast tumors exist, therapies that block activities of ITPKA may offer new options for patients with these tumors. Thus, efforts should be made to develop clinical drugs that selectively target InsP3Kinase activity as well as actin bundling activity of ITPKA.
Collapse
|
20
|
Mundlapati VR, Sahoo DK, Ghosh S, Purame UK, Pandey S, Acharya R, Pal N, Tiwari P, Biswal HS. Spectroscopic Evidences for Strong Hydrogen Bonds with Selenomethionine in Proteins. J Phys Chem Lett 2017; 8:794-800. [PMID: 28145117 DOI: 10.1021/acs.jpclett.6b02931] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Careful protein structure analysis unravels many unknown and unappreciated noncovalent interactions that control protein structure; one such unrecognized interaction in protein is selenium centered hydrogen bonds (SeCHBs). We report, for the first time, SeCHBs involving the amide proton and selenium of selenomethionine (Mse), i.e., amide-N-H···Se H-bonds discerned in proteins. Using mass selective and conformer specific high resolution vibrational spectroscopy, gold standard quantum chemical calculations at CCSD(T), and in-depth protein structure analysis, we establish that amide-N-H···Se and amide-N-H···Te H-bonds are as strong as conventional amide-NH···O and amide-NH···O═C H-bonds despite smaller electronegativity of selenium and tellurium than oxygen. It is in fact, electronegativity, atomic charge, and polarizability of the H-bond acceptor atoms are at play in deciding the strength of H-bonds. The amide-N-H···Se and amide-N-H···Te H-bonds presented here are not only new additions to the ever expanding world of noncovalent interactions, but also are of central importance to design new force-fields for better biomolecular structure simulations.
Collapse
Affiliation(s)
- V Rao Mundlapati
- School of Chemical Sciences, National Institute of Science Education and Research (NISER) , PO- Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
- Homi Bhabha National Institute , Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Dipak Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER) , PO- Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
- Homi Bhabha National Institute , Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Sanat Ghosh
- Tata Institute of Fundamental Research , Homi Bhabha Road, Mumbai 400005, India
| | - Umesh Kumar Purame
- Homi Bhabha National Institute , Training School Complex, Anushakti Nagar, Mumbai 400094, India
- School of Biological Sciences, National Institute of Science Education and Research (NISER) , PO- Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
| | - Shubhant Pandey
- Homi Bhabha National Institute , Training School Complex, Anushakti Nagar, Mumbai 400094, India
- School of Biological Sciences, National Institute of Science Education and Research (NISER) , PO- Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
| | - Rudresh Acharya
- Homi Bhabha National Institute , Training School Complex, Anushakti Nagar, Mumbai 400094, India
- School of Biological Sciences, National Institute of Science Education and Research (NISER) , PO- Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
| | - Nitish Pal
- School of Chemical Sciences, National Institute of Science Education and Research (NISER) , PO- Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
- Homi Bhabha National Institute , Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Prince Tiwari
- School of Chemical Sciences, National Institute of Science Education and Research (NISER) , PO- Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
- Homi Bhabha National Institute , Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Himansu S Biswal
- School of Chemical Sciences, National Institute of Science Education and Research (NISER) , PO- Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
- Homi Bhabha National Institute , Training School Complex, Anushakti Nagar, Mumbai 400094, India
| |
Collapse
|
21
|
Liu A, Sui D, Wu D, Hu J. The activation loop of PIP5K functions as a membrane sensor essential for lipid substrate processing. SCIENCE ADVANCES 2016; 2:e1600925. [PMID: 28138522 PMCID: PMC5262455 DOI: 10.1126/sciadv.1600925] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 10/20/2016] [Indexed: 05/30/2023]
Abstract
Phosphatidylinositol 4-phosphate 5-kinase (PIP5K), a representative member of the phosphatidylinositol phosphate kinase (PIPK) family, is a major enzyme that biosynthesizes the signaling molecule PI(4,5)P2 (phosphatidylinositol 4,5-bisphosphate) in eukaryotic cells. The stringent specificity toward lipid substrates and the high sensitivity to the membrane environment strongly suggest a membrane-sensing mechanism, but the underlying structural basis is still largely unknown. We present a nuclear magnetic resonance (NMR) study on a peptide commensurate with a PIP5K's activation loop, which has been reported to be a determinant of lipid substrate specificity and subcellular localization of PIP5K. Although the activation loop is severely disordered in the crystal structure of PIP5K, the NMR experiments showed that the largely unstructured peptide folded into an amphipathic helix upon its association with the 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) micellar surface. Systematic mutagenesis and functional assays further demonstrated the crucial roles of the amphipathic helix and its hydrophobic surface in kinase activity and membrane-sensing function, supporting a working model in which the activation loop is a critical structural module conferring a membrane-sensing mechanism on PIP5K. The activation loop, surprisingly functioning as a membrane sensor, represents a new paradigm of kinase regulation by the activation loop through protein-membrane interaction, which also lays a foundation on the regulation of PIP5K (and other PIPKs) by membrane lipids for future studies.
Collapse
Affiliation(s)
- Aizhuo Liu
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Dexin Sui
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Dianqing Wu
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06511, USA
| | - Jian Hu
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| |
Collapse
|
22
|
Abstract
To help define the molecular basis of cellular signalling cascades, and their biological functions, there is considerable value in utilizing a high-quality chemical 'probe' that has a well-defined interaction with a specific cellular protein. Such reagents include inhibitors of protein kinases and small molecule kinases, as well as mimics or antagonists of intracellular signals. The purpose of this review is to consider recent progress and promising future directions for the development of novel molecules that can interrogate and manipulate the cellular actions of inositol pyrophosphates (PP-IPs)--a specialized, 'energetic' group of cell-signalling molecules in which multiple phosphate and diphosphate groups are crammed around a cyclohexane polyol scaffold.
Collapse
|
23
|
Inositol polyphosphate multikinase (IPMK) in transcriptional regulation and nuclear inositide metabolism. Biochem Soc Trans 2016; 44:279-85. [PMID: 26862216 DOI: 10.1042/bst20150225] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Inositol polyphosphate multikinase (IPMK, ipk2, Arg(82), ArgRIII) is an inositide kinase with unusually flexible substrate specificity and the capacity to partake in many functional protein-protein interactions (PPIs). By merging these two activities, IPMK is able to execute gene regulatory functions that are very unique and only now beginning to be recognized. In this short review, we present a brief history of IPMK, describe the structural biology of the enzyme and highlight a few recent discoveries that have shed more light on the role IPMK plays in inositide metabolism, nuclear signalling and transcriptional regulation.
Collapse
|
24
|
Baughman BM, Wang H, An Y, Kireev D, Stashko MA, Jessen HJ, Pearce KH, Frye SV, Shears SB. A High-Throughput Screening-Compatible Strategy for the Identification of Inositol Pyrophosphate Kinase Inhibitors. PLoS One 2016; 11:e0164378. [PMID: 27736936 PMCID: PMC5063353 DOI: 10.1371/journal.pone.0164378] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 09/24/2016] [Indexed: 11/22/2022] Open
Abstract
Pharmacological tools-'chemical probes'-that intervene in cell signaling cascades are important for complementing genetically-based experimental approaches. Probe development frequently begins with a high-throughput screen (HTS) of a chemical library. Herein, we describe the design, validation, and implementation of the first HTS-compatible strategy against any inositol phosphate kinase. Our target enzyme, PPIP5K, synthesizes 'high-energy' inositol pyrophosphates (PP-InsPs), which regulate cell function at the interface between cellular energy metabolism and signal transduction. We optimized a time-resolved, fluorescence resonance energy transfer ADP-assay to record PPIP5K-catalyzed, ATP-driven phosphorylation of 5-InsP7 to 1,5-InsP8 in 384-well format (Z' = 0.82 ± 0.06). We screened a library of 4745 compounds, all anticipated to be membrane-permeant, which are known-or conjectured based on their structures-to target the nucleotide binding site of protein kinases. At a screening concentration of 13 μM, fifteen compounds inhibited PPIP5K >50%. The potency of nine of these hits was confirmed by dose-response analyses. Three of these molecules were selected from different structural clusters for analysis of binding to PPIP5K, using isothermal calorimetry. Acceptable thermograms were obtained for two compounds, UNC10112646 (Kd = 7.30 ± 0.03 μM) and UNC10225498 (Kd = 1.37 ± 0.03 μM). These Kd values lie within the 1-10 μM range generally recognized as suitable for further probe development. In silico docking data rationalizes the difference in affinities. HPLC analysis confirmed that UNC10225498 and UNC10112646 directly inhibit PPIP5K-catalyzed phosphorylation of 5-InsP7 to 1,5-InsP8; kinetic experiments showed inhibition to be competitive with ATP. No other biological activity has previously been ascribed to either UNC10225498 or UNC10112646; moreover, at 10 μM, neither compound inhibits IP6K2, a structurally-unrelated PP-InsP kinase. Our screening strategy may be generally applicable to inhibitor discovery campaigns for other inositol phosphate kinases.
Collapse
Affiliation(s)
- Brandi M. Baughman
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, United States of America
- Center for Integrative Chemical Biology and Drug Discovery, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Huanchen Wang
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, United States of America
| | - Yi An
- Center for Integrative Chemical Biology and Drug Discovery, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Dmitri Kireev
- Center for Integrative Chemical Biology and Drug Discovery, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Michael A. Stashko
- Center for Integrative Chemical Biology and Drug Discovery, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Henning J. Jessen
- Institute of Organic Chemistry, Albert-Ludwigs-University of Freiburg, Freiburg 79104, Germany
| | - Kenneth H. Pearce
- Center for Integrative Chemical Biology and Drug Discovery, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Stephen V. Frye
- Center for Integrative Chemical Biology and Drug Discovery, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Stephen B. Shears
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, United States of America
| |
Collapse
|
25
|
Li C, Lev S, Saiardi A, Desmarini D, Sorrell TC, Djordjevic JT. Inositol Polyphosphate Kinases, Fungal Virulence and Drug Discovery. J Fungi (Basel) 2016; 2:jof2030024. [PMID: 29376941 PMCID: PMC5753137 DOI: 10.3390/jof2030024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/23/2016] [Accepted: 08/30/2016] [Indexed: 12/31/2022] Open
Abstract
Opportunistic fungi are a major cause of morbidity and mortality world-wide, particularly in immunocompromised individuals. Developing new treatments to combat invasive fungal disease is challenging given that fungal and mammalian host cells are eukaryotic, with similar organization and physiology. Even therapies targeting unique fungal cell features have limitations and drug resistance is emerging. New approaches to the development of antifungal drugs are therefore needed urgently. Cryptococcus neoformans, the commonest cause of fungal meningitis worldwide, is an accepted model for studying fungal pathogenicity and driving drug discovery. We recently characterized a phospholipase C (Plc1)-dependent pathway in C. neoformans comprising of sequentially-acting inositol polyphosphate kinases (IPK), which are involved in synthesizing inositol polyphosphates (IP). We also showed that the pathway is essential for fungal cellular function and pathogenicity. The IP products of the pathway are structurally diverse, each consisting of an inositol ring, with phosphate (P) and pyrophosphate (PP) groups covalently attached at different positions. This review focuses on (1) the characterization of the Plc1/IPK pathway in C. neoformans; (2) the identification of PP-IP₅ (IP₇) as the most crucial IP species for fungal fitness and virulence in a mouse model of fungal infection; and (3) why IPK enzymes represent suitable candidates for drug development.
Collapse
Affiliation(s)
- Cecilia Li
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia.
| | - Sophie Lev
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia.
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK.
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia.
| | - Tania C Sorrell
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia.
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Westmead, NSW 2145, Australia.
- Westmead Hospital, Westmead, NSW 2145, Australia.
| | - Julianne T Djordjevic
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia.
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Westmead, NSW 2145, Australia.
- Westmead Hospital, Westmead, NSW 2145, Australia.
| |
Collapse
|
26
|
Mechanism of substrate specificity of phosphatidylinositol phosphate kinases. Proc Natl Acad Sci U S A 2016; 113:8711-6. [PMID: 27439870 PMCID: PMC4978281 DOI: 10.1073/pnas.1522112113] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The phosphatidylinositol phosphate kinase (PIPK) family of enzymes is primarily responsible for converting singly phosphorylated phosphatidylinositol derivatives to phosphatidylinositol bisphosphates. As such, these kinases are central to many signaling and membrane trafficking processes in the eukaryotic cell. The three types of phosphatidylinositol phosphate kinases are homologous in sequence but differ in catalytic activities and biological functions. Type I and type II kinases generate phosphatidylinositol 4,5-bisphosphate from phosphatidylinositol 4-phosphate and phosphatidylinositol 5-phosphate, respectively, whereas the type III kinase produces phosphatidylinositol 3,5-bisphosphate from phosphatidylinositol 3-phosphate. Based on crystallographic analysis of the zebrafish type I kinase PIP5Kα, we identified a structural motif unique to the kinase family that serves to recognize the monophosphate on the substrate. Our data indicate that the complex pattern of substrate recognition and phosphorylation results from the interplay between the monophosphate binding site and the specificity loop: the specificity loop functions to recognize different orientations of the inositol ring, whereas residues flanking the phosphate binding Arg244 determine whether phosphatidylinositol 3-phosphate is exclusively bound and phosphorylated at the 5-position. This work provides a thorough picture of how PIPKs achieve their exquisite substrate specificity.
Collapse
|
27
|
Thota SG, Bhandari R. The emerging roles of inositol pyrophosphates in eukaryotic cell physiology. J Biosci 2016; 40:593-605. [PMID: 26333405 DOI: 10.1007/s12038-015-9549-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inositol pyrophosphates are water soluble derivatives of inositol that contain pyrophosphate or diphosphate moieties in addition to monophosphates. The best characterised inositol pyrophosphates, are IP7 (diphosphoinositol pentakisphosphate or PP-IP5), and IP8 (bisdiphosphoinositol tetrakisphosphate or (PP)2-IP4). These energy-rich small molecules are present in all eukaryotic cells, from yeast to mammals, and are involved in a wide range of cellular functions including apoptosis, vesicle trafficking, DNA repair, osmoregulation, phosphate homeostasis, insulin sensitivity, immune signalling, cell cycle regulation, and ribosome synthesis. Identified more than 20 years ago, there is still only a rudimentary understanding of the mechanisms by which inositol pyrophosphates participate in these myriad pathways governing cell physiology and homeostasis. The unique stereochemical and bioenergetic properties these molecules possess as a consequence of the presence of one or two pyrophosphate moieties in the vicinity of densely packed monophosphates are likely to form the molecular basis for their participation in multiple signalling and metabolic pathways. The aim of this review is to provide first time researchers in this area with an introduction to inositol pyrophosphates and a comprehensive overview on their cellular functions.
Collapse
Affiliation(s)
- Swarna Gowri Thota
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500 001, India
| | | |
Collapse
|
28
|
Yu W, Ye C, Greenberg ML. Inositol Hexakisphosphate Kinase 1 (IP6K1) Regulates Inositol Synthesis in Mammalian Cells. J Biol Chem 2016; 291:10437-44. [PMID: 26953345 DOI: 10.1074/jbc.m116.714816] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Indexed: 01/12/2023] Open
Abstract
myo-Inositol, the precursor of all inositol compounds, has pivotal roles in cell metabolism and signaling pathways. Although physiological studies indicate a strong correlation between abnormal intracellular inositol levels and neurological disorders, very little is known about the regulation of inositol synthesis in mammalian cells. In this study, we report that IP6K1, an inositol hexakisphosphate kinase that catalyzes the synthesis of inositol pyrophosphate, regulates inositol synthesis in mammalian cells. Ip6k1 ablation led to profound changes in DNA methylation and expression of Isyna1 (designated mIno1), which encodes the rate-limiting enzyme inositol-3-phosphate synthase. Interestingly, IP6K1 preferentially bound to the phospholipid phosphatidic acid, and this binding was required for IP6K1 nuclear localization and the regulation of mIno1 transcription. This is the first demonstration of IP6K1 as a novel negative regulator of inositol synthesis in mammalian cells.
Collapse
Affiliation(s)
- Wenxi Yu
- From the Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202
| | - Cunqi Ye
- From the Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202
| | - Miriam L Greenberg
- From the Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202
| |
Collapse
|
29
|
Abstract
Eukaryotic cells have ubiquitously utilized the myo-inositol backbone to generate a diverse array of signalling molecules. This is achieved by arranging phosphate groups around the six-carbon inositol ring. There is virtually no biological process that does not take advantage of the uniquely variable architecture of phosphorylated inositol. In inositol biology, phosphates are able to form three distinct covalent bonds: phosphoester, phosphodiester and phosphoanhydride bonds, with each providing different properties. The phosphoester bond links phosphate groups to the inositol ring, the variable arrangement of which forms the basis of the signalling capacity of the inositol phosphates. Phosphate groups can also form the structural bridge between myo-inositol and diacylglycerol through the phosphodiester bond. The resulting lipid-bound inositol phosphates, or phosphoinositides, further expand the signalling potential of this family of molecules. Finally, inositol is also notable for its ability to host more phosphates than it has carbons. These unusual organic molecules are commonly referred to as the inositol pyrophosphates (PP-IPs), due to the presence of high-energy phosphoanhydride bonds (pyro- or diphospho-). PP-IPs themselves constitute a varied family of molecules with one or more pyrophosphate moiety/ies located around the inositol. Considering the relationship between phosphate and inositol, it is no surprise that members of the inositol phosphate family also regulate cellular phosphate homoeostasis. Notably, the PP-IPs play a fundamental role in controlling the metabolism of the ancient polymeric form of phosphate, inorganic polyphosphate (polyP). Here we explore the intimate links between phosphate, inositol phosphates and polyP, speculating on the evolution of these relationships.
Collapse
|
30
|
Inositol phosphate kinase 2 is required for imaginal disc development in Drosophila. Proc Natl Acad Sci U S A 2015; 112:15660-5. [PMID: 26647185 DOI: 10.1073/pnas.1514684112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inositol phosphate kinase 2 (Ipk2), also known as IP multikinase IPMK, is an evolutionarily conserved protein that initiates production of inositol phosphate intracellular messengers (IPs), which are critical for regulating nuclear and cytoplasmic processes. Here we report that Ipk2 kinase activity is required for the development of the adult fruit fly epidermis. Ipk2 mutants show impaired development of their imaginal discs, the primordial tissues that form the adult epidermis. Although disk tissue seems to specify normally during early embryogenesis, loss of Ipk2 activity results in increased apoptosis and impairment of proliferation during larval and pupal development. The proliferation defect is in part attributed to a reduction in JAK/STAT signaling, possibly by controlling production or secretion of the pathway's activating ligand, Unpaired. Constitutive activation of the JAK/STAT pathway downstream of Unpaired partially rescues the disk growth defects in Ipk2 mutants. Thus, IP production is essential for proliferation of the imaginal discs, in part, by regulating JAK/STAT signaling. Our work demonstrates an essential role for Ipk2 in producing inositide messengers required for imaginal disk tissue maturation and subsequent formation of adult body structures and provides molecular insights to signaling pathways involved in tissue growth and stability during development.
Collapse
|
31
|
The new InsP3Kinase inhibitor BIP-4 is competitive to InsP3 and blocks proliferation and adhesion of lung cancer cells. Biochem Pharmacol 2015; 96:143-50. [PMID: 25986882 DOI: 10.1016/j.bcp.2015.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 05/08/2015] [Indexed: 12/30/2022]
Abstract
As ectopic expression of the neuronal inositol-1,4,5-trisphosphate-3-kinase A (InsP3Kinase) in tumor cells increases the metastatic potential, InsP3Kinase is an interesting target for tumor therapy. Recently, we have identified a membrane-permeable InsP3Kinase inhibitor (BAMB-4) exhibiting an IC50-value of 20 μM. Here we characterized a new InsP3Kinase inhibitor which shows a 130-fold lower IC50 value (157 ± 57 nM) as compared to BAMB-4. We demonstrate that this nitrophenolic compound, BIP-4, is non-competitive to ATP but competitive to InsP3, thus exhibits a high selectivity for inhibition of InsP3Kinase activity. Docking analysis suggested a putative binding mode of this molecule into the InsP3Kinase active site. Determination of cellular uptake in lung cancer cells (H1299) revealed that 6% of extracellular BIP-4 is internalized by non-endosomal uptake, showing that BIP-4 is not trapped inside endo/lysosomes but is available to inhibit cellular InsP3Kinase activity. Interestingly, we found that BIP-4 mediated inhibition of InsP3Kinase activity in the two lung cancer cell lines H1299 and LN4323 inhibited proliferation and adhesion at IC50 values of 3 μM or 2 μM, respectively. InsP3Kinase inhibition did not alter ATP-induced calcium signals but significantly reduced the level of Ins(1,3,4,5,6)P5. From these data we conclude that the inhibitory effect of BIP-4 on proliferation and adhesion of lung cancer cells does not result from alterations of calcium but from alterations of inositol phosphate signals. In summary, we reveal that inhibition of cellular InsP3Kinase by BIP-4 impairs proliferation and adhesion and therefore BIP-4 might be a promising compound to reduce the metastatic potential of lung carcinoma cells.
Collapse
|
32
|
A new calmodulin-binding motif for inositol 1,4,5-trisphosphate 3-kinase regulation. Biochem J 2014; 463:319-28. [DOI: 10.1042/bj20140757] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Inositol 1,4,5-trisphosphate 3-kinase regulation by Ca2+/calmodulin involves multiple protein–protein interactions, which form a highly hydrophobic interface and defines a new calmodulin-binding motif. The structural data support that calmodulin binds to an autoinhibitory segment facilitating the kinase activity.
Collapse
|
33
|
Jakob U, Kriwacki R, Uversky VN. Conditionally and transiently disordered proteins: awakening cryptic disorder to regulate protein function. Chem Rev 2014; 114:6779-805. [PMID: 24502763 PMCID: PMC4090257 DOI: 10.1021/cr400459c] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Ursula Jakob
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1048, United States
| | - Richard Kriwacki
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163, United States
| | - Vladimir N. Uversky
- Department of Molecular Medicine, University of South Florida, Tampa, Florida 33612, United States
- Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
| |
Collapse
|
34
|
IP6K structure and the molecular determinants of catalytic specificity in an inositol phosphate kinase family. Nat Commun 2014; 5:4178. [PMID: 24956979 DOI: 10.1038/ncomms5178] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 05/21/2014] [Indexed: 01/27/2023] Open
Abstract
Inositol trisphosphate kinases (IP3Ks) and inositol hexakisphosphate kinases (IP6Ks) each regulate specialized signalling activities by phosphorylating either InsP3 or InsP6 respectively. The molecular basis for these different kinase activities can be illuminated by a structural description of IP6K. Here we describe the crystal structure of an Entamoeba histolytica hybrid IP6K/IP3K, an enzymatic parallel to a 'living fossil'. Through molecular modelling and mutagenesis, we extrapolated our findings to human IP6K2, which retains vestigial IP3K activity. Two structural elements, an α-helical pair and a rare, two-turn 310 helix, together forge a substrate-binding pocket with an open clamshell geometry. InsP6 forms substantial contacts with both structural elements. Relative to InsP6, enzyme-bound InsP3 rotates 55° closer to the α-helices, which provide most of the protein's interactions with InsP3. These data reveal the molecular determinants of IP6K activity, and suggest an unusual evolutionary trajectory for a primordial kinase that could have favored efficient bifunctionality, before propagation of separate IP3Ks and IP6Ks.
Collapse
|
35
|
Lee D, Han S, Woo S, Lee HW, Sun W, Kim H. Enhanced expression and purification of inositol 1,4,5-trisphosphate 3-kinase A through use of the pCold1-GST vector and a C-terminal hexahistidine tag in Escherichia coli. Protein Expr Purif 2014; 97:72-80. [PMID: 24576661 DOI: 10.1016/j.pep.2014.02.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 11/26/2022]
Abstract
Inositol 1,4,5-trisphosphate 3-kinase A (IP3K-A, alternative name: ITPKA) is a neuron-specific enzyme that converts 1,4,5-trisphosphate (IP3) into inositol 1,3,4,5-tetrakisphosphate (IP4) through its kinase domain. In addition, transient overexpression of IP3K-A induces morphological changes in dendritic spines of excitatory synapses in a kinase-independent manner, apparently by modulating the organization of the neuronal cytoskeleton. Although the procurement of a purified recombinant IP3K-A protein would be indispensable for the biochemical elucidation of its physiological roles, production of recombinant IP3K-A has proven technically challenging in conventional Escherichia coli expression systems. These difficulties stem from low enzyme solubility, as well as poor protein quality caused by the tendency of IP3K-A to split into partial fragments. In present study, we newly introduced cold-shock expression vector (pCold1) together with a C-terminal hexahistidine tag (C-HIS) to enhance the expression levels of recombinant IP3K-A in E. coli. Importantly, when compared with other commonly-employed bacterial expression systems, the pCold1 system improved the yield and the purity of full-length IP3K-A due to the exclusion of truncated enzyme forms, and also enhanced the solubility of the enzyme. Furthermore, the functional integrity of purified IP3K-A was confirmed in both kinase activity assay and microtubule binding assay. Recombinant IP3K-A acquired via this modified protocol will be expected to facilitate the exploration of the enzyme's biochemical profile, both structurally and functionally.
Collapse
Affiliation(s)
- Dongmin Lee
- Department of Anatomy, College of Medicine, Korea University, Brain Korea 21, Seoul 136-705, Republic of Korea
| | - Seungrie Han
- Department of Anatomy, College of Medicine, Korea University, Brain Korea 21, Seoul 136-705, Republic of Korea
| | - Seungkyun Woo
- Department of Anatomy, College of Medicine, Korea University, Brain Korea 21, Seoul 136-705, Republic of Korea
| | - Hyun Woo Lee
- Department of Anatomy, College of Medicine, Korea University, Brain Korea 21, Seoul 136-705, Republic of Korea
| | - Woong Sun
- Department of Anatomy, College of Medicine, Korea University, Brain Korea 21, Seoul 136-705, Republic of Korea
| | - Hyun Kim
- Department of Anatomy, College of Medicine, Korea University, Brain Korea 21, Seoul 136-705, Republic of Korea.
| |
Collapse
|
36
|
Peng Z, Maxwell D, Sun D, Ying Y, Schuber PT, Bhanu Prasad BA, Gelovani J, Yung WKA, Bornmann WG. Design and Synthesis of an Inositol Phosphate Analog Based on Computational Docking Studies. Tetrahedron 2014; 70:984-990. [PMID: 25110363 DOI: 10.1016/j.tet.2013.11.092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A virtual library of 54 inositol analog mimics of In(1,4,5)P3 has been docked, scored, and ranked within the binding site of human inositol 1,4,5-trisphosphate 3-kinase A (IP3-3KA). Chemical synthesis of the best scoring structure that also met distance criteria for 3'-OH to -P in Phosphate has been attempted along with the synthesis of (1S,2R,3S,4S)-3-fluoro-2,4-dihydroxycyclohexanecarboxylic acid as an inositol analog, useful for non-invasive visualization and quantitation of IP3-3KA enzymatic activity.
Collapse
Affiliation(s)
- Zhenghong Peng
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - David Maxwell
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Duoli Sun
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Yunming Ying
- Department of Experimental Diagnostic Imaging, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Paul T Schuber
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Basvoju A Bhanu Prasad
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Juri Gelovani
- Department of Experimental Diagnostic Imaging, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - Wai-Kwan Alfred Yung
- Department of Experimental Diagnostic Imaging, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| | - William G Bornmann
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd. Box 603, Houston, TX 77030, USA
| |
Collapse
|
37
|
Thomas MP, Potter BVL. The enzymes of human diphosphoinositol polyphosphate metabolism. FEBS J 2013; 281:14-33. [PMID: 24152294 PMCID: PMC4063336 DOI: 10.1111/febs.12575] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 09/10/2013] [Accepted: 10/15/2013] [Indexed: 12/22/2022]
Abstract
Diphospho-myo-inositol polyphosphates have many roles to play, including roles in apoptosis, vesicle trafficking, the response of cells to stress, the regulation of telomere length and DNA damage repair, and inhibition of the cyclin-dependent kinase Pho85 system that monitors phosphate levels. This review focuses on the three classes of enzymes involved in the metabolism of these compounds: inositol hexakisphosphate kinases, inositol hexakisphosphate and diphosphoinositol-pentakisphosphate kinases and diphosphoinositol polyphosphate phosphohydrolases. However, these enzymes have roles beyond being mere catalysts, and their interactions with other proteins have cellular consequences. Through their interactions, the three inositol hexakisphosphate kinases have roles in exocytosis, diabetes, the response to infection, and apoptosis. The two inositol hexakisphosphate and diphosphoinositol-pentakisphosphate kinases influence the cellular response to phosphatidylinositol (3,4,5)-trisphosphate and the migration of pleckstrin homology domain-containing proteins to the plasma membrane. The five diphosphoinositol polyphosphate phosphohydrolases interact with ribosomal proteins and transcription factors, as well as proteins involved in membrane trafficking, exocytosis, ubiquitination and the proteasomal degradation of target proteins. Possible directions for future research aiming to determine the roles of these enzymes are highlighted.
Collapse
Affiliation(s)
- Mark P Thomas
- Department of Pharmacy & Pharmacology, University of Bath, UK
| | | |
Collapse
|
38
|
Wickramasinghe VO, Savill JM, Chavali S, Jonsdottir AB, Rajendra E, Grüner T, Laskey RA, Babu MM, Venkitaraman AR. Human inositol polyphosphate multikinase regulates transcript-selective nuclear mRNA export to preserve genome integrity. Mol Cell 2013; 51:737-50. [PMID: 24074953 DOI: 10.1016/j.molcel.2013.08.031] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 06/20/2013] [Accepted: 08/14/2013] [Indexed: 01/08/2023]
Abstract
Messenger RNA (mRNA) export from the nucleus is essential for eukaryotic gene expression. Here we identify a transcript-selective nuclear export mechanism affecting certain human transcripts, enriched for functions in genome duplication and repair, controlled by inositol polyphosphate multikinase (IPMK), an enzyme catalyzing inositol polyphosphate and phosphoinositide turnover. We studied transcripts encoding RAD51, a protein essential for DNA repair by homologous recombination (HR), to characterize the mechanism underlying IPMK-regulated mRNA export. IPMK depletion or catalytic inactivation selectively decreases RAD51 protein abundance and the nuclear export of RAD51 mRNA, thereby impairing HR. Recognition of a sequence motif in the untranslated region of RAD51 transcripts by the mRNA export factor ALY requires IPMK. Phosphatidylinositol (3,4,5)-trisphosphate (PIP3), an IPMK product, restores ALY recognition in IPMK-depleted cell extracts, suggesting a mechanism underlying transcript selection. Our findings implicate IPMK in a transcript-selective mRNA export pathway controlled by phosphoinositide turnover that preserves genome integrity in humans.
Collapse
Affiliation(s)
- Vihandha O Wickramasinghe
- The Medical Research Council Cancer Unit, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Stein F, Kress M, Reither S, Piljić A, Schultz C. FluoQ: a tool for rapid analysis of multiparameter fluorescence imaging data applied to oscillatory events. ACS Chem Biol 2013; 8:1862-8. [PMID: 23882997 DOI: 10.1021/cb4003442] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The number of fluorescent sensors and their use in living cells has significantly increased in the past years. Yet, the analysis of data from single cells or cell populations usually remains a very time-consuming enterprise. Here, we introduce FluoQ, a new macro for the image analysis software ImageJ, which enables fast analysis of multiparameter time-lapse fluorescence microscopy data with minimal manual input. FluoQ provides statistical analysis of all measured parameters and delivers the results in multiple graphic and numeric displays. We demonstrate the power of FluoQ by applying the macro to data analysis in the development and optimization of novel FRET reporters for monitoring the performance of calcium/calmodulin-binding inositol trisphosphate kinases A and B (ITPKA and ITPKB) in HeLa cells. We find that conformational changes in the ITPKA-based sensor follow receptor-mediated calcium oscillations. This indicates that ITPKA contributes to the regulation of intracellular calcium transients by limiting inositol trisphosphate levels.
Collapse
Affiliation(s)
- Frank Stein
- European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics Unit, Meyerhofstraße
1, 69117 Heidelberg, Germany
| | - Manuel Kress
- European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics Unit, Meyerhofstraße
1, 69117 Heidelberg, Germany
| | - Sabine Reither
- European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics Unit, Meyerhofstraße
1, 69117 Heidelberg, Germany
| | - Alen Piljić
- European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics Unit, Meyerhofstraße
1, 69117 Heidelberg, Germany
| | - Carsten Schultz
- European Molecular Biology Laboratory (EMBL), Cell Biology and Biophysics Unit, Meyerhofstraße
1, 69117 Heidelberg, Germany
| |
Collapse
|
40
|
Gosein V, Miller GJ. Roles of phosphate recognition in inositol 1,3,4,5,6-pentakisphosphate 2-kinase (IPK1) substrate binding and activation. J Biol Chem 2013; 288:26908-13. [PMID: 23884422 PMCID: PMC3772240 DOI: 10.1074/jbc.m113.487777] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inositol phosphate kinases (IPKs) sequentially phosphorylate inositol phosphates (IPs) to yield a group of small signaling molecules involved in diverse cellular processes. IPK1 (inositol 1,3,4,5,6-pentakisphosphate 2-kinase) phosphorylates inositol 1,3,4,5,6-pentakisphosphate to inositol 1,2,3,4,5,6-hexakisphosphate; however, the mechanism of IP recognition employed by IPK1 is currently unresolved. We demonstrated previously that IPK1 possesses an unstable N-terminal lobe in the absence of IP, which led us to propose that the phosphate profile of the IP was linked to stabilization of IPK1. Here, we describe a systematic study to determine the roles of the 1-, 3-, 5-, and 6-phosphate groups of inositol 1,3,4,5,6-pentakisphosphate in IP binding and IPK1 activation. The 5- and 6-phosphate groups were the most important for IP binding to IPK1, and the 1- and 3-phosphate groups were more important for IPK1 activation than the others. Moreover, we demonstrate that there are three critical residues (Arg-130, Lys-170, and Lys-411) necessary for IPK1 activity. Arg-130 is the only substrate-binding N-terminal lobe residue that can render IPK1 inactive; its 1-phosphate is critical for full IPK1 activity and for stabilization of the active conformation of IPK1. Taken together, our results support the model for recognition of the IP substrate by IPK1 in which (i) the 4-, 5-, and 6-phosphates are initially recognized by the C-terminal lobe, and subsequently, (ii) the interaction between the 1-phosphate and Arg-130 stabilizes the N-terminal lobe and activates IPK1. This model of IP recognition, believed to be unique among IPKs, could be exploited for selective inhibition of IPK1 in future studies that investigate the role of higher IPs.
Collapse
Affiliation(s)
- Varin Gosein
- From the Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | | |
Collapse
|
41
|
Endo-Streeter S, Tsui MKM, Odom AR, Block J, York JD. Structural studies and protein engineering of inositol phosphate multikinase. J Biol Chem 2012; 287:35360-35369. [PMID: 22896696 DOI: 10.1074/jbc.m112.365031] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inositol phosphates (IPs) regulate vital processes in eukaryotes, and their production downstream of phospholipase C activation is controlled through a network of evolutionarily conserved kinases and phosphatases. Inositol phosphate multikinase (IPMK, also called Ipk2 and Arg82) accounts for phosphorylation of IP(3) to IP(5), as well as production of several other IP molecules. Here, we report the structure of Arabidopsis thaliana IPMKα at 2.9 Å and find it is similar to the yeast homolog Ipk2, despite 17% sequence identity, as well as the active site architecture of human IP(3) 3-kinase. Structural comparison and substrate modeling were used to identify a putative basis for IPMK selectivity. To test this model, we re-engineered binding site residues predicted to have restricted substrate specificity. Using steady-state kinetics and in vivo metabolic labeling studies in modified yeast strains, we observed that K117W and K117W:K121W mutants exhibited nearly normal 6-kinase function but harbored significantly reduced 3-kinase activity. These mutants complemented conditional nutritional growth defects observed in ipmk null yeast and, remarkably, suppressed lethality observed in ipmk null flies. Our data are consistent with the hypothesis that IPMK 6-kinase activity and production of Ins(1,4,5,6)P(4) are critical for cellular signaling. Overall, our studies provide new insights into the structure and function of IPMK and utilize a synthetic biological approach to redesign inositol phosphate signaling pathways.
Collapse
Affiliation(s)
- Stuart Endo-Streeter
- Department of Pharmacology and Cancer Biology, and of Biochemistry, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710
| | - Man-Kin Marco Tsui
- Department of Pharmacology and Cancer Biology, and of Biochemistry, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710
| | - Audrey R Odom
- Department of Pharmacology and Cancer Biology, and of Biochemistry, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710
| | - Jeremy Block
- Department of Pharmacology and Cancer Biology, and of Biochemistry, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710
| | - John D York
- Department of Pharmacology and Cancer Biology, and of Biochemistry, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710.
| |
Collapse
|
42
|
Baños-Sanz JI, Sanz-Aparicio J, Whitfield H, Hamilton C, Brearley CA, González B. Conformational changes in inositol 1,3,4,5,6-pentakisphosphate 2-kinase upon substrate binding: role of N-terminal lobe and enantiomeric substrate preference. J Biol Chem 2012; 287:29237-49. [PMID: 22745128 DOI: 10.1074/jbc.m112.363671] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inositol 1,3,4,5,6-pentakisphosphate 2-kinase (IP(5) 2-K) catalyzes the synthesis of inositol 1,2,3,4,5,6-hexakisphosphate from ATP and IP(5). Inositol 1,2,3,4,5,6-hexakisphosphate is implicated in crucial processes such as mRNA export, DNA editing, and phosphorus storage in plants. We previously solved the first structure of an IP(5) 2-K, which shed light on aspects of substrate recognition. However, failure of IP(5) 2-K to crystallize in the absence of inositide prompted us to study putative conformational changes upon substrate binding. We have made mutations to residues on a region of the protein that produces a clasp over the active site. A W129A mutant allowed us to capture IP(5) 2-K in its different conformations by crystallography. Thus, the IP(5) 2-K apo-form structure displays an open conformation, whereas the nucleotide-bound form shows a half-closed conformation, in contrast to the inositide-bound form obtained previously in a closed conformation. Both nucleotide and inositide binding produce large conformational changes that can be understood as two rigid domain movements, although local changes were also observed. Changes in intrinsic fluorescence upon nucleotide and inositide binding are in agreement with the crystallographic findings. Our work suggests that the clasp might be involved in enzyme kinetics, with the N-terminal lobe being essential for inositide binding and subsequent conformational changes. We also show how IP(5) 2-K discriminates between inositol 1,3,4,5-tetrakisphosphate and 3,4,5,6-tetrakisphosphate enantiomers and that substrate preference can be manipulated by Arg(130) mutation. Altogether, these results provide a framework for rational design of specific inhibitors with potential applications as biological tools for in vivo studies, which could assist in the identification of novel roles for IP(5) 2-K in mammals.
Collapse
Affiliation(s)
- José Ignacio Baños-Sanz
- Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006-Madrid, Spain
| | | | | | | | | | | |
Collapse
|
43
|
Gosein V, Leung TF, Krajden O, Miller GJ. Inositol phosphate-induced stabilization of inositol 1,3,4,5,6-pentakisphosphate 2-kinase and its role in substrate specificity. Protein Sci 2012; 21:737-42. [PMID: 22362712 DOI: 10.1002/pro.2049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 02/07/2012] [Accepted: 02/08/2012] [Indexed: 01/25/2023]
Abstract
Inositol phosphate kinases (IPKs) sequentially phosphorylate inositol phosphates (IPs) on their inositol rings to yield an array of signaling molecules. IPKs must possess the ability to recognize their physiological substrates from among a pool of over 30 cellular IPs that differ in numbers and positions of phosphates. Crystal structures from IPK subfamilies have revealed structural determinants for IP discrimination, which vary considerably between IPKs. However, recent structures of inositol 1,3,4,5,6-pentakisphosphate 2-kinase (IPK1) did not reveal how IPK1 selectively recognizes its physiological substrate, IP5, while excluding others. Here, we report that limited proteolysis has revealed the presence of multiple conformational states in the IPK1 catalytic cycle, with notable protection from protease only in the presence of IP. Further, a 3.1-Å crystal structure of IPK1 bound to ADP in the absence of IP revealed decreased order in residues 110-140 within the N-lobe of the kinase compared with structures in which IP is bound. Using this solution and crystallographic data, we propose a model for recognition of IP substrate by IPK1 wherein phosphate groups at the 4-, 5-, and 6-positions are recognized initially by the C-lobe with subsequent interaction of the 1-position phosphate by Arg130 that stabilizes this residue and the N-lobe. This model explains how IPK1 can be highly specific for a single IP substrate by linking its interactions with substrate phosphate groups to the stabilization of the N- and C-lobes and kinase activation.
Collapse
Affiliation(s)
- Varin Gosein
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada, H3G 1Y6
| | | | | | | |
Collapse
|
44
|
Abstract
Somatic missense mutations in PIK3CA, which encodes the p110α catalytic subunit of phosphoinositide 3-kinases (PI3Ks), occur frequently in human cancers. Activating mutations spread across multiple domains, some of which are located at inhibitory contact sites formed with the regulatory subunit p85α. PIK3R1, which encodes p85α, also has activating somatic mutations. We find a strong correlation between lipid kinase and lipid binding activities, for both wild-type (WT) and a representative set of oncogenic mutant complexes of p110α/p85α. Lipid binding involves both electrostatic and hydrophobic interactions. Activation caused by a phosphorylated receptor tyrosine kinase (RTK) peptide binding to the p85α N-terminal SH2 domain (nSH2) induces lipid binding. This depends on the polybasic activation loop as well as a conserved hydrophobic motif in the C-terminal region of the kinase domain. The hotspot E545K mutant largely mimics the activated WT p110α. It shows the highest basal activity and lipid binding, and is not significantly activated by an RTK phosphopeptide. Both the hotspot H1047R mutant and rare mutations (C420R, M1043I, H1047L, G1049R and p85α-N564D) also show increased basal kinase activities and lipid binding. However, their activities are further enhanced by an RTK phosphopeptide to levels markedly exceeding that of activated WT p110α. Phosphopeptide binding to p110β/p85α and p110δ/p85α complexes also induces their lipid binding. We present a crystal structure of WT p110α complexed with the p85α inter-SH2 domain (iSH2) and the inhibitor PIK-108. Additional to the ATP-binding pocket, an unexpected, second PIK-108 binding site is observed in the kinase C-lobe. We show a global conformational change in p110α consistent with allosteric regulation of the kinase domain by nSH2. These findings broaden our understanding of the differential biological outputs exhibited by distinct types of mutations regarding growth factor dependence, and suggest a two-tier classification scheme relating p110α and p85α mutations with signalling potential.
Collapse
|
45
|
Wang H, Falck JR, Hall TMT, Shears SB. Structural basis for an inositol pyrophosphate kinase surmounting phosphate crowding. Nat Chem Biol 2011; 8:111-6. [PMID: 22119861 PMCID: PMC3923263 DOI: 10.1038/nchembio.733] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 08/30/2011] [Indexed: 01/16/2023]
Abstract
Inositol pyrophosphates (such as IP7 and IP8) are multifunctional signaling molecules that regulate diverse cellular activities. Inositol pyrophosphates have 'high-energy' phosphoanhydride bonds, so their enzymatic synthesis requires that a substantial energy barrier to the transition state be overcome. Additionally, inositol pyrophosphate kinases can show stringent ligand specificity, despite the need to accommodate the steric bulk and intense electronegativity of nature's most concentrated three-dimensional array of phosphate groups. Here we examine how these catalytic challenges are met by describing the structure and reaction cycle of an inositol pyrophosphate kinase at the atomic level. We obtained crystal structures of the kinase domain of human PPIP5K2 complexed with nucleotide cofactors and either substrates, product or a MgF(3)(-) transition-state mimic. We describe the enzyme's conformational dynamics, its unprecedented topological presentation of nucleotide and inositol phosphate, and the charge balance that facilitates partly associative in-line phosphoryl transfer.
Collapse
Affiliation(s)
- Huanchen Wang
- Inositol Signaling Group, Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA.
| | | | | | | |
Collapse
|
46
|
Kitamura M, Nishimoto H, Aoki K, Tsukamoto M, Aoki S. Molecular recognition of inositol 1,4,5-trisphosphate and model compounds in aqueous solution by ditopic Zn(2+) complexes containing chiral linkers. Inorg Chem 2010; 49:5316-27. [PMID: 20420391 DOI: 10.1021/ic1004038] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report on molecular recognition of inositol 1,4,5-trisphosphate (Ins(1,4,5)P(3)), an important intracellular second messenger, and some related model compounds, cyclohexanediol bisphosphate derivatives (CDP(2)), by ditopic Zn(2+) complexes containing chiral linkers ((S,S)- and (R,R)-11) in aqueous solution at physiological pH. A crystal structure analysis of (S,S)-11 indicated that the distance between two Zn(2+) ions (6.8 A) is suitable for accommodating two phosphate groups at the 4- and 5-positions of Ins(1,4,5)P(3) and two phosphate groups of trans-1,2-CDP(2). (1)H NMR, (31)P NMR, potentiometric pH, and isothermal calorimetric titration data indicate that (S,S)-11 forms 1:1 complexes with (S,S)- and (R,R)-1,2-CDP(2) at pH 7.4 and 25 degrees C. The apparent 1:1 complexation constants (log K(app)) for (S,S)-11-(S,S)-1,2-CDP(2) and (S,S)-11-(R,R)-1,2-CDP(2) (K(app) = [(S,S)-11-1,2-CDP(2) complex]/[(S,S)-11][1,2-CDP(2)] (M(-1))) were determined to be 7.6 +/- 0.1 and 7.3 +/- 0.1, respectively, demonstrating that both enantiomers of 11 bind to chiral trans-1,2-CDP(2) to almost the same extent. The log K(app) value of 6.3 was obtained for a 1:1 complex of (S,S)-11 with cis-1,3-CDP(2), while a small amount of 2:1 (S,S)-11-cis-1,3-CDP(2) was detected, as evidenced by electrospray ionization mass spectrometry (ESI-MS). In contrast, 11 formed several complexes with trans-1,4-CDP(2). On the basis of isothermal titration calorimetry data for (S,S)- and (R,R)-11 with Ins(1,4,5)P(3), it was concluded that 11 forms a 2:1 complex with Ins(1,4,5)P(3), in which the first molecule of 11 binds to the 4- and 5-phosphates of Ins(1,4,5)P(3) and the second molecule of 11 binds to the 1- and 5-phosphates.
Collapse
Affiliation(s)
- Masanori Kitamura
- Faculty of Pharmaceutical Sciences, Tokyo University of Science,2641 Yamazaki, Noda 278-8510, Japan
| | | | | | | | | |
Collapse
|
47
|
Schell MJ. Inositol trisphosphate 3-kinases: focus on immune and neuronal signaling. Cell Mol Life Sci 2010; 67:1755-78. [PMID: 20066467 PMCID: PMC11115942 DOI: 10.1007/s00018-009-0238-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 12/14/2009] [Accepted: 12/18/2009] [Indexed: 11/28/2022]
Abstract
The localized control of second messenger levels sculpts dynamic and persistent changes in cell physiology and structure. Inositol trisphosphate [Ins(1,4,5)P(3)] 3-kinases (ITPKs) phosphorylate the intracellular second messenger Ins(1,4,5)P(3). These enzymes terminate the signal to release Ca(2+) from the endoplasmic reticulum and produce the messenger inositol tetrakisphosphate [Ins(1,3,4,5)P(4)]. Independent of their enzymatic activity, ITPKs regulate the microstructure of the actin cytoskeleton. The immune phenotypes of ITPK knockout mice raise new questions about how ITPKs control inositol phosphate lifetimes within spatial and temporal domains during lymphocyte maturation. The intense concentration of ITPK on actin inside the dendritic spines of pyramidal neurons suggests a role in signal integration and structural plasticity in the dendrite, and mice lacking neuronal ITPK exhibit memory deficits. Thus, the molecular and anatomical features of ITPKs allow them to regulate the spatiotemporal properties of intracellular signals, leading to the formation of persistent molecular memories.
Collapse
Affiliation(s)
- Michael J Schell
- Department of Pharmacology, Uniformed Services University, 4301 Jones Bridge Rd, Bethesda, MD 20814, USA.
| |
Collapse
|
48
|
Inositol 1,3,4,5,6-pentakisphosphate 2-kinase is a distant IPK member with a singular inositide binding site for axial 2-OH recognition. Proc Natl Acad Sci U S A 2010; 107:9608-13. [PMID: 20453199 DOI: 10.1073/pnas.0912979107] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Inositol phosphates (InsPs) are signaling molecules with multiple roles in cells. In particular (InsP(6)) is involved in mRNA export and editing or chromatin remodeling among other events. InsP(6) accumulates as mixed salts (phytate) in storage tissues of plants and plays a key role in their physiology. Human diets that are exclusively grain-based provide an excess of InsP(6) that, through chelation of metal ions, may have a detrimental effect on human health. Ins(1,3,4,5,6)P(5) 2-kinase (InsP(5) 2-kinase or Ipk1) catalyses the synthesis of InsP(6) from InsP(5) and ATP, and is the only enzyme that transfers a phosphate group to the axial 2-OH of the myo-inositide. We present the first structure for an InsP(5) 2-kinase in complex with both substrates and products. This enzyme presents a singular structural region for inositide binding that encompasses almost half of the protein. The key residues in substrate binding are identified, with Asp368 being responsible for recognition of the axial 2-OH. This study sheds light on the unique molecular mechanism for the synthesis of the precursor of inositol pyrophosphates.
Collapse
|
49
|
Sauer K, Cooke MP. Regulation of immune cell development through soluble inositol-1,3,4,5-tetrakisphosphate. Nat Rev Immunol 2010; 10:257-71. [PMID: 20336153 PMCID: PMC2922113 DOI: 10.1038/nri2745] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The membrane lipid phosphatidylinositol-3,4,5-trisphosphate (PtdInsP(3)) regulates membrane receptor signalling in many cells, including immunoreceptor signalling. Here, we review recent data that have indicated essential roles for the soluble PtdInsP(3) analogue inositol-1,3,4,5-tetrakisphosphate (InsP(4)) in T cell, B cell and neutrophil development and function. Decreased InsP(4) production in leukocytes causes immunodeficiency in mice and might contribute to inflammatory vasculitis in Kawasaki disease in humans. InsP(4)-producing kinases could therefore provide attractive drug targets for inflammatory and infectious diseases.
Collapse
Affiliation(s)
- Karsten Sauer
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California 92037, USA.
| | | |
Collapse
|
50
|
Baños-Sanz JI, Villate M, Sanz-Aparicio J, Brearley CA, González B. Crystallization and preliminary X-ray diffraction analysis of inositol 1,3,4,5,6-pentakisphosphate kinase from Arabidopsis thaliana. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:102-6. [PMID: 20057083 PMCID: PMC2805549 DOI: 10.1107/s1744309109051057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Accepted: 11/26/2009] [Indexed: 11/10/2022]
Abstract
Inositol 1,3,4,5,6-pentakisphosphate kinase (IP(5) 2-K) is an enzyme involved in inositol metabolism that synthesizes IP(6) (inositol 1,2,3,4,5,6-hexakisphosphate) from inositol 1,3,4,5,6-pentakisphosphate (IP(5)) and ATP. IP(6) is the major phosphorus reserve in plants, while in mammals it is involved in multiple cellular events such as DNA editing and chromatin remodelling. In addition, IP(6) is the precursor of other highly phosphorylated inositols which also play highly relevant roles. IP(5) 2-K is the only enzyme that phosphorylates the 2-OH axial position of the inositide and understanding its molecular mechanism of substrate specificity is of great interest in cell biology. IP(5) 2-K from Arabidopsis thaliana has been expressed in Escherichia coli as two different fusion proteins and purified. Both protein preparations yielded crystals of different quality, always in the presence of IP(6). The best crystals obtained for X-ray crystallographic analysis belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 58.124, b = 113.591, c = 142.478 A. Several diffraction data sets were collected for the native enzyme and two heavy-atom derivatives using a synchrotron source.
Collapse
Affiliation(s)
- Jose Ignacio Baños-Sanz
- Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física ‘Rocasolano’, CSIC, Serrano 119, 28006 Madrid, Spain
| | - Maider Villate
- Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física ‘Rocasolano’, CSIC, Serrano 119, 28006 Madrid, Spain
| | - Julia Sanz-Aparicio
- Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física ‘Rocasolano’, CSIC, Serrano 119, 28006 Madrid, Spain
| | | | - Beatriz González
- Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física ‘Rocasolano’, CSIC, Serrano 119, 28006 Madrid, Spain
| |
Collapse
|